THE LIFE-HISTORY OF A BEE-FLY (SPOGOSTYLUM 



ANALE SAY) PARASITE OF THE LARVA OF A TIGER 



BEETLE (CICINDELA SCUTELLARIS SAY VAR. 



LECONTEI HALD.). 



By Victor E. Shelford. 



PAGE 



I. Introduction 213 



II. Life History of the Parasite {Spogostylum') 215 



1. Adult Habit 215 



2. Egg Laying 215 



3. Egg 216 



4. Larva 217 



5. Pupa and Adult 219 



III. Other Species , 222 



IV. Ecological and Geographic Distribution of Parasite and Host 222 



V. Summary 225 



VI . Acloiowledgments and Bibliography 225 



I. Introduction. 



The life histories of the American BombyHidae are imper- 

 fectly known and this lack of knowledge is due largely to the 

 difficulty of studying parasitic forms. The species in question 

 is never abundant and consequently much time has been con- 

 sumed in getting together the data for the account here pre- 

 sented. Near Chicago it occurs on dry sandy places where 

 there is much vegetation and where the sand is slightly blackened 

 with humus. The data presented were collected mainly in 

 connection with work upon the host which involved collecting 

 and rearing to maturity about a thousand host larvse. 



The larva of the parasite was first discovered in 1904 but 

 none was successfully reared until 1906; the method of egg 

 laying was not successfully observed until 1908 and 1909 while 

 attempts to study the adult habits in 1910 and 1911 were only 

 partially successful. 



Life History of the Host. 



Cicindela sciitellaris Say var. Lecontei Hald. is found in areas 

 of dry sand to which considerable humus has been added by 

 decaA^ng vegetation (Wickham '02, Shelford '07, '11). Adults 

 are present near Chicago from April to June and again in Sep- 

 tember. The fall individuals are those emerging from the 

 pupal stage and are not sexually mature. These individuals 

 pass the winter in the ground, become sexually mature after 

 the warm days in April and deposit eggs in May and early June. 



213 



